F-DOPA uptake may be seen in inflammatory tissue or benign tumors. Correlations with history, physical examination, laboratory examination, CT, MRI, and histology are necessary for optimal diagnosis.

IntroductionLhermitte-Duclos disease or dysplastic gangliocytoma of the cerebellum is an extremely rare tumor. It is a slowly enlarging mass within the cerebellar cortex. The majority of cases are diagnosed in the third or fourth decade of life.Case presentationWe report the case of a 37-year-old Caucasian woman who underwent positron emission tomography-computed tomography with fluorine-18-fluorodeoxyglucose for evaluation of a solitary lung node. No pathological uptake was detected in the solitary lung node but the positron emission tomography-computed tomography of her brain showed intense tracer uptake, suggestive of a malignant neoplasm, in a mass in her left cerebellar lobe. Our patient had experienced two years of occipital headache and movement disorder. Subsequently, magnetic resonance imaging was performed with contrast agent administration, showing a large subtentorial mass in her left cerebellar hemisphere, with compression and dislocation of the fourth ventricle. Metabolic data provided by positron emission tomography and morphological magnetic resonance imaging views were fused in post-processing, allowing a diagnosis of dysplastic gangliocytoma with increased glucose metabolism. Total resection of the tumor was performed and histological examination confirmed the diagnosis of Lhermitte-Duclos disease.ConclusionsOur case indicates that increased uptake of fluorine-18-fluorodeoxyglucose may be misinterpreted as a neoplastic process in the evaluation of patients with Lhermitte-Duclos disease, but supports the usefulness of integrated positron emission tomography-magnetic resonance imaging in the exact pathophysiologic explanation of this disease and in making the correct diagnosis. However, an accurate physical examination and exact knowledge of clinical data is of the utmost importance.

Aim To investigate the progression-free survival (PFS) and the overall survival (OS) in a population affected by primary brain tumors (PBT) evaluated by [ 18 F]-l-dihydroxyphenylalanine ([ 18 F] FDOPA) positron emission tomography/computed tomography (PET/CT). Materials and methods 133 subjects with PBT (65 women and 68 men, mean age 45 ± 10 years old) underwent 18 F FDOPA PET/CT after treatment. Of them, 68 (51.2%) were Grade II, 34 (25.5%) were Grade III and 31 (23.3%) were Grade IV. PET/CT was scored as positive or negative and standardized uptake value ratio (SUVr) was calculated as the ratio between SUVmax of the lesion vs. that of the background. Patients have been observed for a mean of 24 months. Results The outcome of [ 18 F] FDOPA PET/CT scan was significantly related to the OS and PFS in Grade II gliomas. In Grade II PBT, the OS proportions at 24 months were 100% in subjects with a negative PET/CT scan and 82% in those with a positive scan. Gehan-Breslow-Wilcoxon test showed a significant difference in the OS curves (P = 0.03) and the hazard-ratio was equal to 5.1 (95% CI of ratio 1.1-23.88). As for PFS, the proportion at 24 months was 90% in subjects with a negative PET/CT scan and 58% in those with a positive scan. Gehan-Breslow-Wilcoxon test showed a significant difference in the OS curves (P = 0.007) and the hazard-ratio was equal to 4.1 (95% CI of ratio 1.3-8). We did not find any significant relationship between PET outcome and OS and PFS in Grade III and IV PBT. Conclusions A positive [ 18 F] FDOPA PET/CT scan is related to a poor OS and PFS in subjects with low-grade PBT. This imaging modality could be considered as a prognostic factor in these subjects.Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

The principle of legitimate expectations becomes a new limiter of administrative action, further strengthening the legal positions of the subject. The author shows that the principle of legitimate expectations is aimed at protecting the positions of the subject. This doctrine belongs to administrative law and is associated with the ethical principles of morality, loyalty and, above all, good faith. Influenced by the Spanish experience, this is now a widespread approach in South American countries where the doctrine of legitimate expectation is mentioned in administrative procedures. This is particularly relevant predominantly in the context of administrative actions. The author highlights the idea that in South America, legal practice directly points to the principle of good faith as an effective means of preventing a negative attitude towards an individual. The paper analyses the features of the application of this principle in such South American countries as Venezuela, Colombia, Brazil, Costa Rica, Peru, Bolivia and Uruguay. At the same time, the author notes that there are several factors that affect the operation of the principle, do not depend on normative acts, and may limit the protection of the legal positions of subjects. The most important of these is the process of transition to democracy, which is still ongoing in these countries and is strongly influenced by persistent primary dynamics such as the logic of so-called caudilism, idiosyncratic legal traditions and political practices, and complex and conflicting social, ethical and cultural contexts.